Robust nickel silicate catalysts with high Ni loading for CO2 methanation.

CO 2 is the main component of greenhouse gases and also an important carbon source. The hydrogenation of CO 2 to methane using Ni-based catalysts can not only alleviate CO 2 emissions but also obtain useful fuels. However, Ni-based catalysts face one major problem of the sintering of Ni nanoparticles in the process of CO 2 methanation. Thus, this work has synthesized a series of efficient and robust nickel silicate catalysts (NiPS-X) with different nickel content derived from nickel phyllosilicate by the hydrothermal method. It was found that the Ni loading plays a critical role in the structure and catalytic performance of the NiPS-X catalysts. The catalytic performance gradually increases with the increase of Ni loading. In particular, the highly dispersed NiPS-1.6 catalyst with a high Ni loading of 34.3 wt% could obtain the CO 2 conversion greater than 80%, and the methane selectivity was close to 100% for 48 h at 330 °C and the GHSV of 40,000 mL·g -1 ·h -1 . The excellent catalytic property can be assigned to the high dispersion of Ni nanoparticles and the strong interaction between the active component and the carrier, which is derived from a unique layered silicate structure with lots of nickel phyllosilicate and a large number of Lewis acid sites.